Having lived through it,i can now say this to you with a bit

句子的主干就是 i can now say this to you
这句话有省略
when death was a useful but purely intellectual concept.这句话是一个完整的状语从句,
than后面省略了跟前面相同的主谓结构
这里比较的是时间 是now和when从句的比较!
因为主谓结构都相同,所以省略了
还原之后如下
i can now say this to you with a bit more certainty than (i can say this to you) when death was a useful but purely intellectual concept
翻译：度过这次死亡之旅后,相比于以前只知道死亡有用,但纯粹是思想概念时,我现在可以更自信地和你们说这些.
这里理解的关键就是对than 的比较对象的理解!
注意体会!

Having lived through it,i can now say this to you with a bit more certainty than when death was a useful but purely intellectual concept.
I can now say this to you 这是本句的主干。Having lived through it是...

　　您的理解也许有误。首先把Having lived through it这个状语从句剥离出来，后面的句子也要分开看：先看I can say this to you,这句话您肯定能理解。但是注意我把now剥离出来了，now应该怎么看呢？？其实now有个比较对象，不知道您看到more。。。than。。。了没有？？？这个比较句式就是把now和when时间状语从句比较了。而这个but呢 只不过是转折了一...

Having lived through it, I can now say this to you with a bit more certainty
than when death was a useful but purely intellectual concept.
这话怎么断句？
主句: I can now say this to you；
条件状语:...

with a bit more certainty 是状语，than when death was a useful but purely intellectual concept整句是修饰certainty ，but这里是表示转折意思的连词，连接useful 和purely intellectual 这两个形容词，构成转折，死亡是有用但是很纯粹的知识概念那这句话直白的翻译是什么？已经经历过死亡，...